1. Technical Field of the Invention
This invention generally relates to the field of non-destructive techniques for measurement of composite materials. More specifically, the invention relates to improved techniques for the measurement of 3-dimensional composite articles.
2. Description of the Prior Art
In recent years, use of composite materials has grown in the aerospace and other commercial industries. Composite materials offer significant improvements in performance, however they are difficult to manufacture and thus require strict quality control procedures during manufacturing. In addition, composite materials lend themselves well to the manufacture of parts having irregular shapes. Non-destructive evaluation (“NDE”) techniques have been developed as a method for the identification of defects in composite structures, such as, for example, the detection of inclusions, delaminations and porosities. Conventional NDE methods are typically slow, labor-intensive and costly. As a result, the testing procedures adversely increase the manufacturing costs associated with composite structures.
For parts having irregular surfaces, the measurement data is preferably correlated to positional 3-dimensional data. For these parts, determination of the shape of the part is key to correlating the measurement to a position on the part. Prior art methods for scanning composite parts having irregular shapes required that the part being scanned be positioned on a table and secured in a known position, thereby providing a starting reference point for the scan. For large and/or irregularly shaped objects, the table or other means required to position a part are expensive and frequently specific for only one part.
According to the prior art methods, scanning of complex shaped parts to determine the 3-dimensional shape of the part required multiple scans from several different poses or views. These scans are frequently slow in determining the 3-dimensional shape an object. Thus, there exists a need for a method and apparatus for the rapid acquisition of 3-dimensional position data.